A car of mass 1000kg is travelling at 20m/s when it
collides with a wall.
The front of the car collapses in 0.1 seconds,
by which time the car is at rest.
Calculate the deceleration of the car.
Calculate the force exerted by the wall on the car.

Using the work energy theorem. what is the velocity of a 850kg car after starting at rest when 13,000j of work is done to it.

On a day when the barometer reads 75.23 cm, a reaction vessel holds 250 ml of ideal gas at 20 celsius. an oil manometer ( ρ= 810 kg/m^3) reads the pressure in the vessel to be 41 cm of oil and below atmospheric pressure. what volume will the gas occupy under s. t.p.?

Two identical stars with mass m orbit around their center of mass. each orbit is circular and has radius r, so that the two stars are always on opposite sides of the circle. (a) find the gravitational force of one star on the other. (b) find the orbital speed of each star and the period of the orbit. (c) how much energy would be required to separate the two stars to infinity?